Package 'ITALICS'

Title: ITALICS
Description: A Method to normalize of Affymetrix GeneChip Human Mapping 100K and 500K set
Authors: Guillem Rigaill, Philippe Hupe
Maintainer: Guillem Rigaill <[email protected]>
License: GPL-2
Version: 2.65.0
Built: 2024-10-03 03:16:27 UTC
Source: https://github.com/bioc/ITALICS

Help Index


add info to quartet annotation

Description

This function merge information obtain from the getQuartet function and a given table

Usage

addInfo(quartet, dat)

Arguments

quartet

list obtain through the getQuartet Function

dat

a data.frame with additionnal information it must contain a fsetid and fid column

Value

a data.frame similar to the quartetInfo item of quartet plus additionnal column

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


GLAD analysis

Description

Glad Analysis ot the genomic profile

Usage

analyseCGH(data, amplicon, deletion, deltaN, forceGL, param, nbsigma, ...)

Arguments

data

A data frame containing SNP's intensity, chromosome and position on the genome. data must have a Chr, X and LogRatio columns

amplicon

see the amplicon parameter in the daglad function

deletion

see the deletion parameter in the daglad function

deltaN

see the deltaN parameter in the daglad function

forceGL

see the forceGL parameter in the daglad function

param

see the param parameter in the daglad function

nbsigma

see the nbsigma parameter in the daglad function

...

Other daglad parameters.

Value

An object of class profileCGH

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can

visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Compute the copy number of each SNP from its quartets intensities

Description

This function removes the LogRatio column of the snpInfo data.frame. Then compute the copy number of each SNP having its quartet intensities. And return the snpInfo data.frame with the newly computed LogRatio.

Usage

fromQuartetToSnp(quartetInfo, snpInfo, cIntensity="quartetLogRatio", nLog=1)

Arguments

quartetInfo

A table containing the quartet intensities and other quartet information. It must have a column called : fsetid.

snpInfo

A table containing snp information.

cIntensity

A vector containing the names of the quartet information to be aggregate. For example quartetLogRatio.

nLog

The position of the field which will be named LogRatio in the snpInfo data.frame. For example if cIntensity = c("a", "b") and you want b to be considered as the LogRatio you should set nLog=2

Value

return the data.frame snpInfo with additionnal columns.

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Function to get from snp to quartet

Description

This function put the smoothing value of each SNP in front of its corresponding quartet in the quartetInfo data.frame.

Usage

fromSnpToQuartet(quartetInfo, profilSNP)

Arguments

quartetInfo

a data frame containing all the quartet values plus there GC content, fragment length and GC content and Quartet effect

profilSNP

a data frame, corresponding to the profileValues argument of a profilCGH object (see GLAD)

Value

return the data.frame quartetInfo with an additionnal column: "Smoothing" corresponding to the estimated smoothing value.

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Elimination of badly predicted probes

Description

This function eliminate badly predicted probes using a regression table and an estimated model given by the function getModel or getBestBICModelLight. Then it computes the corrected intensity.

Usage

getConfDat(confidence, quartetInfo, model)

Arguments

confidence

The confidence interval : 0.95

quartetInfo

A Regression table containing the variables in the model

model

The class lm object given by the function getModel

Value

A data frame with the corrected intensity. Only goodly predicted probes are taken into account. SNP's with more than 8 badly predicted probes get a NA.

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Correction

Description

This function computes the corrected intensity.

Usage

getCorrection(effet, model, regTab)

Arguments

effet

The name of the biological effect

model

The class lm object given by the getModel function

regTab

The regression table used to estimate the linear model, and containing the variables in the model

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Effet

Description

This function retrieves the estimated biological effect

Usage

getEffet(effet, model, regTab)

Arguments

effet

The name of the biological effect

model

The class lm object given by the getModel function

regTab

The regression table used to estimate the linear model, and containing the variables in the model

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Regression Model

Description

Computes the linear regression model and and return an object of class lm.

Usage

getModel(formule, response, regTab)

Arguments

formule

A symbolic description of the term of the model. It is a string

response

The parameter you want to explain (the response) : the SNP "LogRatio". Y is a string

regTab

A Regression table containing the variables in the model

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Function to retrieve the information of each quartet

Description

This function retrieve information of each quartet. This function use the pd.mapping50k.xba240, pd.mapping50k.hind240, pd.mapping250k.sty and pd.mapping250k.nsp package.

Usage

getQuartet(pkgname, snpInfo)

Arguments

pkgname

the chip type pd.mapping50k.xba240, pd.mapping50k.hind240, pd.mapping250k.sty or pd.mapping250k.nsp

snpInfo

a data frame containing SNPs position along the genome

Value

return a list with two fields. fid : containing the position of each quartet on the CEL file. quartetInfo : a data fame containing the columns : fsetid, fid, FL (fragment length) and GC (content of the quartet)

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Correction

Description

This function retrieves the residual values

Usage

getResidu(model)

Arguments

model

The class lm object given by the getModel function

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Function to retrieve the chromosome and the position of each SNP on a given Affymetrix SNP array

Description

This function retrieve the chromosome and position in bp of each SNP of a given Affymetrix SNP array. This function use the pd.mapping50k.xba240, pd.mapping50k.hind240, pd.mapping250k.sty and pd.mapping250k.nsp package.

Usage

getSnpInfo(pkgname)

Arguments

pkgname

the chip type pd.mapping50k.xba240, pd.mapping50k.hind240, pd.mapping250k.sty or pd.mapping250k.nsp

Value

Return a data.frame with five columns : fsetid, dbsnp_rs_id, Chr, X and fragment_length corresponding to the fsetid, the rs_id, the chromosome, the position on the chromosome and the PCR amplified fragment length respectively.

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


Affymetrix SNP chip normalization

Description

Normalize and analyse Affymetrix SNP array 100K and 500K set (see the vignette)

Usage

ITALICS(quartetInfo, snpInfo, confidence=0.95, iteration=2, 
    formule="Smoothing+QuartetEffect+FL+I(FL^2)+I(FL^3)+GC+I(GC^2)+I(GC^3)", prc=0.3,
    amplicon=2.1, deletion=-3.5, deltaN=0.15, forceGL=c(-0.2,0.2), param=c(d=2), nbsigma=1, ... )

Arguments

quartetInfo

a data frame containing all the raw quartet intensities plus there GC content, fragment length, and Quartet effect

snpInfo

a data frame containing SNPs position along the genome and raw copy number

confidence

The confidence interval. After the last bias estimation step, quartets outside this confidence interval are flagged. The lower confidence is, the more quartets will be flagged. See also the parameter prc.

iteration

The number of iteration you d'like to do

formule

A symbolic description of the term of the model. The default value of formule means that we want correct the observed quartetLogRatio using the estimated copy number (Smoothing), the Quartet Effect, the quartet Fragment Length (FL) and the quartet GC content.

prc

prc is a frequence (between 0 and 1). After the final iteration of ITALICS, badly predicted probes are flagged (see also the parameter confidence). Only SNPs having more than prc of their probes non-flagged are kept for the final GLAD analysis. The higher prc is, the more SNPs are removed before the final GLAD analysis.

amplicon

see the amplicon parameter in the daglad function

deletion

see the deletion parameter in the daglad function

deltaN

see the deltaN parameter in the daglad function

forceGL

see the forceGL parameter in the daglad function

param

see the param parameter in the daglad function

nbsigma

see the nbsigma parameter in the daglad function

...

Other daglad parameters.

Details

The function ITALICS implements the methodology which is described in the article : ITALICS: an algorithm for normalization and DNA copy number calling for Affymetrix SNP arrays (Rigaill et al., Bioinformatics Advance Access published on February 5, 2008).

The principle of the ITALICS algorithm: ITALICS, is a normalization method that estimates both the biological and the non-relevant effects in an alternate and iterative way to accurately remove the non-relevant effects.

ITALICS deals with known systematic sources of variation such as the GC-content of the quartets, the PCR amplified fragment length and the GC-content of the PCR amplified fragment . It also takes into account the quartet effect which corresponds to the fact that some quartets systematically have a small intensity while others tend to have a high intensity. ITALICS is also able to correct spatial artifacts which sometimes arise on Affymetrix SNP arrays 100K and 500K set.

Value

Return an object of class profileCGH

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].

Examples

## Not run: 
## step to get the path of the HF0844_Hind.CEL file
ITALICSDataPATH <- attr(as.environment(match("package:ITALICSData",search())),"path")
filename <- paste(ITALICSDataPATH,"/extdata/HF0844_Hind.CEL", sep="")
quartetEffectFile <- paste(ITALICSDataPATH,"/data/Hind.QuartetEffect.csv", sep="")

## load quartet effect
quartetEffect <- read.table(quartetEffectFile, sep=";", header=TRUE)

## load annotation using the pd.mapping50k.xba24 or pd.mapping50k.hind240 or  pd.mapping250k.sty or pd.mapping250k.nsp package
headdetails <- readCelHeader(filename[1])
pkgname <- cleanPlatformName(headdetails[["chiptype"]])
snpInfo <- getSnpInfo(pkgname)
quartet <- getQuartet(pkgname, snpInfo)

## read cel files and format data
tmpExprs <- readCelIntensities(filename, indices=quartet$fid)
quartet$quartetInfo$quartetLogRatio <- readQuartetCopyNb(tmpExprs)
quartet$quartetInfo <- addInfo(quartet, quartetEffect)
snpInfo <- fromQuartetToSnp(cIntensity="quartetLogRatio", quartetInfo=quartet$quartetInfo, snpInfo=snpInfo)


## ITALICS normalization
profilSNPHind <- ITALICS(quartet$quartetInfo, snpInfo,
    formule="Smoothing+QuartetEffect+FL+I(FL^2)+I(FL^3)+GC+I(GC^2)+I(GC^3)")

## plot the profile
data(cytoband)
plotProfile(profilSNPHind, Smoothing="Smoothing", Bkp=TRUE, cytoband = cytoband)

## End(Not run)

Read PM probes of selected quartets and compute the quartet intensity

Description

This function read the cel files and return the raw-value of each quartet = mean of allele A and B

Usage

readQuartetCopyNb(tmpExprs)

Arguments

tmpExprs

A vector of the perfect match intensity of allele A and B of the quartets. This vector should be sorted in a specific order. See the example given in the help of the ITALICS function.

Value

return a vector with the raw-value of each quartet

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].


ITALICS training

Description

Estimation of the quartet effect based on several normal sample chips

Usage

trainITALICS (dir,  amplicon=2.1, deletion=-3.5, deltaN=0.15, forceGL=c(-0.2,0.2), param=c(d=2), nbsigma=1, ...)

Arguments

dir

The directory containing the normal sample chips. All theses chips should be of the same type hind, xba, nsp or sty. Only .CEL files be considered

amplicon

see the amplicon parameter in the daglad function

deletion

see the deletion parameter in the daglad function

deltaN

see the deltaN parameter in the daglad function

forceGL

see the forceGL parameter in the daglad function

param

see the param parameter in the daglad function

nbsigma

see the nbsigma parameter in the daglad function

...

Other daglad parameters.

Details

The ITALICS function take into account a quartet effect which is computed on a reference data set of normal women samples. The ITALICSData provide quartetEffect for the Xba, Hind, Sty and Nsp chip computed on our own reference data set.

We recommand that you use your own reference data set to compute the quartet Effect by using the trainITALICS function. ITALICS reference data should contain only woman normal samples. Furthermore we recommand that you check that none of these chip have obvious spatial artifact. To so read the cel files using the read.affybatch (form the affy package). Then use the image function on the obtain affybatch object.

Value

a data.frame with two column fsetid and quartetEffect

Note

People interested in tools dealing with array CGH analysis and DNA copy number analysis can visit our web-page http://bioinfo.curie.fr.

Author(s)

Guillem Rigaill, [email protected].

Source

Institut Curie, [email protected].